1. Technical Field
The present invention relates to a method and associated structure for excising laminate chip carriers from a panel.
2. Related Art
Conventional methods of excising laminate chip carriers from a production panel, such as methods using mechanical routing and diamond saws, require a xe2x80x9ckerfxe2x80x9d or finite separation between excised chip carriers, which limits the number of chip carriers that can be formed from a given panel. The practical kerf width is typically at least about 1.5 mm inasmuch as the fabrication cost becomes prohibitively too expensive if the kerf width is below about 1.5 mm. This minimum kerf width of 1.5 mm is about 30% of the width of the 5 mm chip carriers in current use. In addition, chip carriers that include advanced materials (e.g., a copper-Invar-copper sandwich) are difficult to machine with mechanical methods.
A method is needed for excising chip carriers from a panel, wherein the method is suitable for advanced materials (e.g., a copper-Invar-copper sandwich) currently used in multilayered structures, and wherein the kerf width is negligibly small.
The present invention provides a method for excising cells of a panel, comprising the steps of:
focusing a laser beam on a surface of a panel, wherein the laser beam has a wavelength between about 500 nanometers and about 600 nanometers; and
moving the panel relative to the laser beam in a geometric pattern, such that at least one cell of the panel is excised.
The present invention provides a laser structure, comprising:
a panel having an organized configuration of at least two adjacent cells, wherein a kerf between said adjacent cells has a width between about 2 microns and about 75 microns; and
a laser beam focused within the kerf, wherein the laser beam has a wavelength between about 500 nanometers and about 600 nanometers.
The present invention has the advantage of providing a method for forming chip carriers from a panel, such that the kerf width is negligibly small.
The present invention has the advantage of being suitable for advanced materials (e.g., , a copper-Invar-copper sandwich), currently used in multilayered structures.
The present invention has the advantage of being relatively inexpensive; i.e.; the present invention has little or no consumables, while the routers bits and diamond saws of conventional methods must be replaced periodically.